| 摘要 |
<p>The invention relates to a metal halide lamp provided with a discharge vessel (3) with a ceramic wall (31) and a filling which comprises besides mercury and a halogen also Na, Tl and one or several of the elements from the group formed by Sc, Y and lanthanides. According to the invention, the filling also contains Mg. It is achieved thereby that the luminous efficacy of the lamp remains substantially constant over a long period.</p> |
